Process of producing soluble salts of aluminum.



Parana? ent ies.

MELVILLE F. COOLBAUGH, OF RAPID CITY, AND ELW YN H. QUINNEY, Oli PIERRE,

SOUTH DAKOTA.

PROCESS OF PRODUCING SOLUBLE SALTS OF ALUMINUM.

Specification of Letters Patent.

Patented Apr. 4, 1916.

No Drawing. Original application filed June 2, 1913, Serial No. 771,244.Divided and this application filed July 7, 1914. Serial No. 849,598.

.3! '0 all whom it may concern Be it known that we, MnLviLLn F. Coon.BAUGH and ELWYN H. Qnmnnr, citizens of the United States, and residents,respectively, of Rapid City, in the county of Pennington and State ofSouth Dakota, and Pierre, in the county of Hughes and State of SouthDakota, have made certain new and useful Improvements in Processes ofProducing Soluble Salts of Aluminum, of which the following is aspecification.

Our invention relates to improvements in' processes for producingsoluble salts of aluminum from kaolin and other silicous andargillaceous earths, rocks,,or minerals containing no potash, in whichcom-pounds of aluminum exist in an insoluble form.

An object of our invention is to provide a simple process for producingaluminum sulfate, and one which is inexpensive.

A further object of our invention is to provide a process which isapplicable to rocks, earths or minerals which are found in abundance,and which form therefore a con venient supply of raw material.

Other objects and advantages will appear in the following specificationand the novel steps of the process will be particularly pointed out inthe appended claim.

'This application is-adivision of a prior application, Serial No.771,2l4, filed June 2, 1913. V

In carrying out our process we make use of kaolin or other rocks,shales, or clays.

These are first crushed or ground to pass through an eighty mesh screen.The powdered material is then thoroughly mixed with gypsum or limestonewhich has been previously crushed to the same fineness. The proportionsof the argillaeeous and silicious material and the gypsum or limestonewill vary in accordance with the composition-of the rock, earth orminerals. When gypsum is used two and eight-tenths parts of gypsum byweight should be added to each one part of silica by weight contained inthe kaolin or other rocks, clays or shales to be treated. If limestoneis used one and seven-tenths parts of limestone by weight should beadded for each one part of silica by weight contained in the kaolin orother rocks, shales and clays to be treated. In the treatment ofsubstances of the nature described above which contain lime as one oftheir constituents the amount of limeor gypsum to be added should bedecreased by the amount which is already cdntained in the materials tobe treated. The mixture of the finely ground argillaceous materials andlime or gypsum is heated to incipient fusion, then cooled quickly andcrushed to a powder. The powder is then released with water containingsulfuric acid in the proportion of three parts of sulfuric acid byweight to each one part of alumina by Weight. The alumina as aluminumsulfate is then separated from the solution by crystallization. If toolittle sulfuric acid is used the alumina will not be dissolved out fullyand if too much sulfuric acid is used the lime will be brought down insuch quantities as to interfere with the proper crystallization of thealumina from the solution. The yield of alumina is ordinarily fromninety-three to ninety-eight per cent. of that contained in the kaolinand other rocks, shales and clays treated.

In the foregoing specification the specific examples are given by way ofillustration only, and it will be understood that the proportions inwhich the various substances are brought togethermay vary withoutdeparting from the spirit and scope of the invention.

To claim:

The herein described. process of producing soluble salts of aluminumfrom-potashfree argillaceous and silicious rocks, earths the aluminumsulfate from the resulting solution by crystallization.

MELVILLE F. COOLBAUGH. ELWYN H. QUINNEY. WVitnesses for- Melville F.Coolbaugh: C. M. PooL,

R. L. SMITH. \Vitness'es for Elwyn H. C. F. BUTTERFIELD, HARfiY PRESTON.

or minerals containing insoluble compounds of aluminum, which consistsin reducing the rocks, earths or minerals to a powdered form, mixingtherewith gypsum in the proportion of two and eight-tenths parts ofgypsum by weight to each one part of silica l weight contained in Slll lrocks,'enrths, 01' minerals, heating the mixture toincipient fusion,cooling quickly, low-hing the product with dilute sulfuric acid, nndseparating Quinney Copies of this patent may he obtained for five centseach, by addressing the Commissioner of Patents,

Washington, D. G.

